(4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid 4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester, method of synthesizing thereof, and molecular electronic device using the same

ABSTRACT

A new compound derivative that can be used to form a unit molecular film as a rectifier in a molecular electronic device, a new rectifying compound (4,5,9,10-tetrahydro-pyren-2-yl)-carbamic acid 4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester and its derivative (4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid 4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester, and methods of synthesizing the compounds are provided.

BACKGROUND OF THE INVENTION

This application claims the priority of Korean Patent Application No.2003-48664 filed on Jul. 16, 2003, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein in its entiretyby reference.

1. Field of the Invention

The present invention relates to a compound derivative, in which anelectron acceptor and an electron donor are coupled, and moreparticularly, to a compound derivative of carbamate, a method ofsynthesizing the same, and a molecular device using the same.

2. Description of the Related Art

A molecular electronic or a molecular optical device that has beencurrently reported is mainly in the form of an electronic device, has abasic structure of two metal electrodes and an organic molecular layerdisposed between two metal electrodes. The organic molecule isconfigured to have a characteristic of organic semiconductor between themolecule two metal electrodes. In this case, the dimension of theorganic molecule is in a range of a few nano meters.

Generally, the structure of the molecular device is determined from thedisposition method of the organic molecule between the two electrodes,however, the structure can broadly be divided into two structures, i.e.,a horizontal and a vertical structure. The horizontal structure has aconfiguration that an organic compound is disposed between the two metalelectrodes placed on a same plane. That is, after forming a gap havingnano distance between the two electrodes according to an existingsemiconductor manufacturing process, the organic compound is disposed inthe gap. While, the vertical structure is formed that a lower electrodeis first formed, and an organic compound is placed on the lowerelectrode, and then an upper electrode is placed on the organiccompound.

Until the present time, the organic molecular device material requiredfor the development of the molecular electronic device has been soughtout, focusing mainly on the functional purposes, such as acharacteristic of molecular wire, a molecular switch, and a molecularrectifier. These technical fields have been studied mostly in advancedcountries including U.S.A and Europe as the development of nanotechnology.

The development history of the molecular rectifying device has the samechronicle as the development of the molecular electronic device. Thenecessity of development of a molecular device was first proposedthrough a desire to develop a device utilizing the diode characteristic,i.e., an organic semiconductor characteristic of a molecular rectifyingmaterial. Aviram and Ratner of IBM in 1974 introduced a method offormation of a device having a molecular diode rectifying characteristicusing a unit molecular characteristic.

According to Aviram and Ratner, when an electron donor (D) and anelectron acceptor (A) in a molecule exist in the form of a sigma bondwhich acts as a spacer, a polarization will occur in the molecule withone directional polarization. After the polarized molecules are arrangedin one direction, that is, when forming an electrondonor-spacer-electron acceptor structure, a metal electrode on each sideis connected, and current will flow in one direction.

This hypothesis was proven by Mattern and his co-workers in 1999 througha partial experiment. They reported that a rectifying characteristic wasrealized from the experiment carried out by forming an organic LB(Langmuir film) between two electrodes. Also, Metzger group found thatthe rectifying characteristic can be realized in π-bond instead ofσ-bond. Professor M. A. Reed et al. in Yale University have reportedthat a rectifying diode characteristic can be generated by using anelectric potential difference between two metals, such as gold andtitanium, in an asymmetric organic compound which has no electrondonor-spacer-electron acceptor.

Despite of efforts to develop a rectifying diode device using an organicmolecular characteristic, a clear and direct proof regarding therectifying characteristic of the molecular electronic device, as towhether it is generated from the organic molecular characteristic hasnot been disclosed yet. Up to the present time, the question of therectifying characteristic of the molecular device using an organicmolecule can not be explained whether it comes from the solecharacteristic of the organic compound or it is a phenomenon occurredbetween the two metals including the organic molecule.

Accordingly, there is a strong desire to develop a new molecularrectifying material that can explicate the rectifying characteristic ofmolecular electronic device. However, the development of a molecularrectifying material is very difficult. Particularly, a syntheticdifficultness of an organic compound is considered as a big hindrancefor developing a molecular rectifying material.

For example, when an electron donor and an electron acceptor areco-existed in a reactor, a precipitation, generally in the form of asalt, will occur due to a charge transfer between the two molecules. Forthis reason, synthesizing a covalent compound having an electrondonor-sigma bond-electron acceptor required for forming the molecularelectron rectifying material is practically difficult.

SUMMARY OF THE INVENTION

The present invention provides a new donor-sigma-acceptor compoundderivative obtained through a coupling reaction between(4-sulfanyl-alkyl)-3,5-dinitro-benzyl alcohol as an electron acceptorand 2-aminopyrene as an electron donor.

The present invention also provides a method of synthesizing thecompound derivative.

The present invention also provides a molecular electronic device usingthe compound derivative.

According to an aspect of the present invention, there is provided thata compound performing as a molecular rectifying action having thefollowing chemical formula.

where R represents hydrogen, a methyl radical, an alkyl radical, or anacetyl radical, and n can be an integer between 1 and 25. Particularly,there is provided a compound that R is an acetyl radical, and n is 1.

According to another aspect of the present invention, it is providedthat a molecular diode device composed of a first electrode, a secondelectrode opposite side of the first electrode, and molecular filmformed by combining a compound having above chemical formula with thesecond electrode on a surface of the second electrode.

Also, according to another aspect of the present invention, there isprovided a molecular logic circuit device which is a logic gate formedby arranging molecular diode device as unit device, wherein themolecular diode device is composed of a first electrode, a secondelectrode opposite side of the first electrode, and molecular filmformed by combining a compound having above chemical formula with thesecond electrode on a surface of the second electrode.

According to another aspect of the present invention, there is provideda method of synthesizing a compound comprising preparing4,5,9,10-tetrahydro-pyren-2-yl-amine, preparing 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate, and obtaining a compound havingabove chemical formula by a coupling reaction between4,5,9,10-tetrahydro-pyren-2-yl-amine and 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate, and wherein the compoundperforms molecular rectifying action.

Here, the preparing the 4,5,9,10-tetrahydro-pyren-2-yl-amine comprisessynthesizing 2-nitro-4,5,9,10-tetrahydro-pyrene by reactingtetrahydro-pyrene with nitric acid, and synthesizing the4,5,9,10-tetrahydro-pyren-2-yl-amine by reducing the2-nitro-4,5,9,10-tetrahydro-pyrene.

At this time, the reduction reaction uses tin chloride (SnCl₂) as acatalyst.

Also, preparing the 4-acetylsulfanyl methyl-3,5-dinitro-benzylchloroformate comprises preparing thioacetic acid4-hydroxymethyl-2,6-dinitro-benzyl ester, and synthesizing4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate by reactingthioacetic acid 4-hydroxymethyl-2,6-dinitro-benzyl ester withtrichlorophosgene.

An action to activate the 4,5,9,10-tetrahydro-pyren-2-yl-amine canfurther be performed using a basic catalyst before a coupling reaction.At this time, the basic catalyst can be triethylamine as a third amineradical.

The coupling reaction can be performed using a pyridine group catalyst.The pyridine group catalyst is dimethylaminopyridine.

A method of manufacturing a molecular electronic device includingforming a molecular film on a surface of the first electrode between thecompound having above chemical formula and a surface of the firstelectrode and forming a second electrode on the molecular film, and acharacteristic of molecular device are reported.

According to the present invention, there is provided a new compound,i.e., (4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester that can be used asa rectifying material in a molecular electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a chemical formula of(4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester, a compoundderivative according to an embodiment of the present invention;

FIG. 2 shows reactions for forming(4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester according to anembodiment of the present invention;

FIG. 3 is a Quartz Crystal Microbalance (QCM) data graph for proving aformation of self assembling molecular film of molecular electronicdevice on a surface of gold electrode according to an embodiment of thepresent invention;

FIG. 4A is a schematic diagram of an unit molecular diode device towhich a compound derivative is applied according to the presentinvention;

FIG. 4B is a circuit diagram of an unit molecular diode device to whicha compound derivative is applied according to the present invention;

FIG. 4C is a graph showing a current-voltage characteristic of a unitmolecular diode device depicted in FIG. 4A;

FIG. 5 is a perspective view of diode device arrayed in 3×3 rowsaccording to the present invention;

FIGS. 6A and 6B are schematic diagrams of circuit and operation of anAND gate to be formed by molecular device according to an embodiment ofthe present invention; and

FIGS. 7A and 7B are schematic diagrams of circuit and operation of an ORgate to be formed by molecular devices according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be described more fully withreference to the accompanying drawings in which preferred embodiment ofthe invention are shown. This invention may, however be embodied in manydifferent forms and should not be construed as being limited to theembodiments set forth herein, rather, these embodiments are provided sothat this disclosure is thorough and complete, and fully conveys theconcept of the invention to those skilled in the art. In the drawings,the thickness of layers and regions are exaggerated for clarity. Tofacilitate understanding, identical reference numerals have been used,where possible, to designate identical elements that are common to thefigures.

In an embodiment of the present invention, tetrahydro-pyrene is used asan electron donor, and a new compound having a thiol radical (S⁻) in aparticular location in the tetrahydro-pyrene is provided. Also, a methodof manufacturing the new compound is provided. In this case,4-alkylsufanyl-alkyl-3,5-dinitro-benzyl-alcohol or3,5-dinitro-benzyl-alcohol is used as a electron acceptor.

A new compound derivative having a basic configuration ofdonor-sigma-bonding-acceptor-SR as depicted in FIG. 1 as a result ofcoupling reaction of the electron donor with the electron acceptor and amethod of manufacturing is provided.

FIG. 1 is a chemical formula of(4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester.

Referring to FIG. 1, R represents hydrogen, an alkyl radical, or anacetyl radical, and n represents an integer between 1 and 25.

A compound derivative having a configuration ofDonor-sigma-bonding-Acceptor-SR as depicted in FIG. 1 according to anembodiment of the present invention can be used as an electrondonor-acceptor organic material for a new molecular electronic devicehaving a molecular rectifying characteristic.

Also, by utilizing a conducting probe-atomic force-microscopy (CP-AFM)or a scanning tunneling microscopy (STM), a measurement ofcurrent-voltage between two electrodes and a direction of current flowmay be performed. Particularly, the organic material is applicable tosynthesize a vertical or a horizontal type molecular electronic devicehaving a rectifying characteristic. Also, such rectifying material canbe applied to a molecular electron array device and a logic circuitusing the molecular electron array.

In order to apply the compound derivative having chemical formuladepicted in FIG. 1 to a molecular device, fixing the compound derivativeto an electrode of the molecular electronic device is required.Therefore, in the embodiment of the present invention, a method offixing the compound derivative to the electrode of molecular electronicdevice, and a method of manufacturing a unit molecular device using themethod of fixing the compound derivative to the electrode andcharacteristics of molecular device will be described.

First, an example of synthesizing a compound derivative according to thepresent invention having a basic configuration as depicted in FIG. 1will be described referring to a reaction depicted in FIG. 2.

Synthesis Method

FIG. 2 shows a reaction formula for describing the method ofsynthesizing (4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester according to anembodiment of the present invention.

Referring to the reaction formula depicted in FIG. 2, the method ofsynthesizing (4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester according to thechemical formula of FIG. 1 and the fixation method of the(4,5,9,10-Tetrahydro-pyren-2-yl)-carbamic acid4-(2-methylsulfanyl-alkyl)-3,5-dinitro-benzyl ester to the electrode ofthe molecular electronic device comprise the following steps.

That is, a first step 210 for synthesizing2-nitro-4,5,9,10-tetrahydro-pyrene 215 from tetrahydro-pyrene 211reaction with nitric acid, and a second step 230 for synthesizing4,5,9,10-tetrahydro-pyren-2-yl-amine 235 from a reaction between2-nitro-4,5,9,10-tetrahydro-pyrene 215 and SnCl₂ which is a reductionagent.

Also, the steps can include a third step 250 for synthesizing4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate 255 from areaction between thioacetic acid 4-hydroxymethyl-2,6-dinitro-benzylester 251 and trichlorophosgene.

Also, the steps can further include a fourth step 270 for synthesizingthioacetic acid 2,6-dinitro-4-(4,5,9,10-tetrahydro-2-ylcarbamoyloxymethyl)-benzyl ester 275 from a reaction between4,5,9,10-tetrahydro-pyren-2-yl-amine 235 and 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate 255.

The above steps can further include a fifth step 290 for forming a thinfilm 295 using the obtained material, i.e., thioacetic acid2,6-dinitro-4-(4,5,9,10-tetrahydro-2-ylcarbamoyloxy methyl)-benzyl ester275 as the molecular electronic device.

First Step (210 in FIG. 2)

At the first step 210 in FIG. 2, the compound2-nitro-4,5,9,10-tetrahydro-pyrene 215 can be synthesized from thecompound tetrahydro-pyrene 211 by a nucleophilic reaction. That is, theelectron rich location 2 or 7 of the tetrahydro-pyrene 211 attacks theelectron deficient intermediate location of the nitro compound.

More specifically, after dissolving the 4,5,9,10-tetrahydro-pyrene 211in glacial acetic acid, by reacting the solution with fuming nitricacid, the 2-nitro-4,5,9,10-tetrahydro-pyrene 215 was synthesizedaccording to the first step 210. The first step 210 reaction isperformed at temperature of 0˜30° C., preferably at 15˜20° C. for 5˜10minutes with stirring enough to have complete mixing. Concentration ofnitric acid can be 2˜3M per 1 mole of 4,5,9,10-tetrahydro-pyrene 211,preferably 2.5M. A solvent can be any solvent that does not affect thereaction, but preferably acetic acid or dichloromethane.

Second Step (230 in FIG. 2)

At the second step 230 in FIG. 2, tin chloride (SnCl₂) as a reductionagent can be used for the reaction when the2-nitro-4,5,9,10-tetrahydro-pyrene 215 is reduced to4,5,9,10-tetrahydro-pyren-2-yl-amine 235, for higher yield.

More specifically, the 4,5,9,10-tetrahydro-pyren-2-yl-amine 235 issynthesized by substituting a nitro radical of the2-nitro-4,5,9,10-tetrahydro-pyrene 215 to amine radical using tinchloride (SnCl₂), i.e., a reduction agent. Methods for substituting thenitro radical to the amine radical can include a method using a metalcatalyst like Raney nickel Ni, but an activation of Raney nickel cannotbe easily achieved. Therefore, in the embodiment of the presentinvention, tin chloride is used as the catalyst.

Solvent can be an organic solvent that does not affect the reaction 230,preferably acetylacetate anhydride or ethanol anhydride. Aqueoussolution of 15˜25 equivalent sodium ethylene diamine tetraacetic acid(sodium EDTA), preferably 18˜20 equivalent sodium EDTA can be added tothe solution to remove excessive tin used for the reaction afterreaction.

Third Step (250 in FIG. 2)

At the second step 250 in FIG. 2, 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate 255 can be obtained through areaction between thioacetic acid 4-hydroxymethyl-2,6-dinitro-benzylester 251 and trichlorophosgene compound.

More specifically, in order to synthesize chloroformate radical usinghydroxy radical of the thioacetic acid4-hydroxymethyl-2,6-dinitro-benzyl ester 251, trichlorophosgene is used.In a conventional method for synthesizing the chloroformate radical, aliquefied phosgene gas was used, but in the embodiment of the presentinvention, a much safer method of synthesizing the chloroformate radicalusing trichlorophosgene is introduced.

Preferably, one equivalent trichlorophosgene is used to thioacetic acid4-hydroxymethyl-2,6-dinitro-benzyl ester 251. Preferably, the reactioncatalyst is one equivalent of a weak salt of pyridine group. Thereaction condition has to be an anhydride condition, accordingly,anhydrous dichloromethane is suitable for the solvent.

Preferably, the reaction time is for 5˜7 hours. Preferably, the reactiontemperature is 0° C. maintained in an ice bath, and more preferably, thetemperature is maintained at 0° C. throughout the reaction includingwhen adding and after adding the pyridine and the trichlorophosgene.

Fourth Step (270 in FIG. 2)

As the same manner as the third step reaction in FIG. 2, in order toobtain thioacetic acid2,6-dinitro-4-(4,5,9,10-tetrahydro-2-ylcarbamoyloxy methyl)-benzyl ester275, the synthesized 4,5,9,10-tetrahydro-pyren-2-yl-amine 235 and the4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate 255 are coupledunder a basic catalyst.

Reaction solvent can be an anhydride solvent, and more preferably, ananhydrous dichloromethane. Catalyst that can be used to activate the4,5,9,10-tetrahydro-pyren-2-yl-amine 235 is a third amine group, morepreferably, 0.9˜1.0 equivalent of triethylamine.

Preferably, after dissolving the 4,5,9,10-tetrahydro-pyren-2-yl-amine235 and the triethylamine in the dichloromethane solvent, the solutionis mixed for 10˜20 minutes. Afterward, the 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate 255 is added to the solution andpreferably the solution is mixed for approximately an hour withstirring. A pyridine group catalyst, preferably 0.9˜1.0 equivalent ofdimethyl aminopyridine can be added to the solution. Preferably,reaction time is 20˜24 hours, more preferably, 24 hours.

As the reaction progresses, white solid precipitation occurs. The whitesolid precipitation can be separated by filtering. Preferably,contaminants are removed by washing the white solid several time using asolvent like dichloromethane that does not dissolve the white solid,more preferably, re-crystallization can be performed using a solventlike ester group in which the white solid dissolves. Particularly, it ispreferable to try to re-crystallize the white solid after dissolving itto tetrahydrofurane by adding hexane.

Fifth Step (290 in FIG. 2)

Finally, in order to fix the organic molecule 275 synthesized from thefourth step 270 on the molecular electronic device electrode, a selfassembling method is used. That is, a self assembled molecular layer(SAM) 295, i.e., 4,5,9,10-tetrahydro-pyren-2-yl-carbamic acid4-mercaptomethyl-3,5-dinitro-benzyl ester is formed on the goldelectrode 287 by dipping the gold electrode substrate 297 having amolecular device on its surface in a solution containing thioacetic acid2,6-dinitro-4-(4,5,9,10-tetrahydro-2-ylcarbamoyloxy methyl)-benzyl ester275 with an acidic or a basic catalyst, or without an acidic or a basiccatalyst.

Preferably, the solution can be an organic solution having a highsolubility in which the thioacetic acid2,6-dinitro-4-(4,5,9,10-tetrahydro-2-ylcarbamoyloxy methyl)-benzyl ester275 synthesized in the fourth step is dissolved.

Preferable the organic solvent can be alcohol, tetrahydrofurane (THF),or dimethyl formamide (DMF), more preferably, oxygen free and anhydroussolvent prepared using a freeze-pump-thaw method. When forming a selfassembled molrcular layer, a temperature is maintained in a range of0˜80° C. under oxygen free and anhydrous atmosphere. The moleculardevice is dipped in the solution conventionally for 24˜48 hours.Afterward, it is washed by pouring a solvent on the surface of themolecular device. At this time, the solvent for washing the moleculardevice can be alcohol, THF, or distilled water, more preferably, it iswashed first with alcohol or THF and then it is washed with distilledwater.

Sixth Step (295 in FIG. 2)

As the same manner as described above, a self assembled molecular film295 on a surface of the gold 297 electrode to be used to a moleculardevice can be fabricated.

Seventh Step (FIG. 6)

A molecular device composed of metal/molecular film/metal can bemanufactured by depositing an upper electrode on the molecular filmdevice.

An effectiveness of the method of synthesizing according to theembodiment of the present invention is proved through actualexperiments.

[Experiments]

Synthesis of 2-nitro-4,5,9,10-tetrahydro-pyrene 215 in FIG. 2

A water bath that can maintain reactants and a reactor temperature at20° C. is prepared. 3.1 g (15 mmol) of tetrahydro-pyrene 211 was pouredin a two-circle rounded bottom flask having a magnetic stirrer placed inthe water bath, and the reactant was dissolved adding 200 ml of glacialacetic acid. 13.5 ml of fuming acid was slowly added to the solutionextending over 5 minutes while stirring the solution. After mixing thereactants for 5 more minutes, the solution was quenched by adding 100 mlof ice water, then yellow solids were formed. The solution containingyellow solid was further stirred for approximately one hour. Afterfiltering the solution, the obtained yellow solids were washed with coldwater. The yellow solids were dissolved in dichloromethane solvent.Afterward, 3.56 g (14.2 mmol) of a light yellow solid, i.e.,2-nitro-4,5,9,10-tetrahydro-pyrene 215 was obtained by purifying thesolution passing through a silica gel chromatography column using 10%acetylactate and a hexane group solvent. In this case, yield was 94.3%.

The structure of the product was examined using a hydrogen nuclearmagnetic resonance (NMR), and found that it matched the structure ofcompound numeral 215 depicted in FIG. 2. The hydrogen NMR obtained was[¹H NMR (400 MHz, CDCl₃) (ppm): 7.98 (2H, s), 7.26 (1H, dd), 7.16 (2H,t), 2.97 (8H, m); MS: m/z (%) 189 (10), 202 (15), 221 (M⁺, 100)]

Synthesis of 4,5,9,10-tetrahydro-pyren-2-yl-amine 235 in FIG. 2

An oil bath that can maintain reactants and a reactor temperature at100° C. with a thermometer is prepared. A 100 ml of two-circle roundedbottom flask (hereinafter, flask) having a condenser and a stirrer isplaced in the oil bath. 1.0 g (3.98 mmol) of2-nitro-4,5,9,10-tetrahydro-pyrene 215 and 4.48 g (19.0 mmol) of tinchloride (SnCl₂) were poured into the flask. After dissolving thereactants in 25 ml of anhydrous acetylactate in the flask, it wasreacted for 12 hours with stirring.

After cooling the reactant, 20 equivalents of sodium EDTA solution wasadded to the solution to remove unreacted excessive tin. White solidprecipitations were removed by filtering. A product was extracted byadding ethyl ether to the filtrate, and the solution was concentrated byremoving the ethyl ether under reduced pressure. 0.85 g (3.83 mmol) ofyellow solid, i.e., 4,5,9,10-tetrahydro-pyren-2-yl-amine 235 wasobtained purifying through a silica gel chromatography column. In thiscase, yield was 96%.

The structure of the product was examined using a hydrogen nuclearmagnetic resonance (NMR), and found that it matched the structure ofcompound numeral 235 depicted in FIG. 2. The hydrogen NMR obtained was[¹H NMR (400 MHz, CDCl₃) (ppm): 7.08 (3H, s), 6.46 (2H, s), 3.5 (2H,brs), 2.85 (8H, m). MS: m/z (%) 189 (20), 202 (35), 251 (M⁺, 100)]

Synthesis of 4-acetylsulfanyl methyl-3.5-dinitro-benzyl chloroformate255 in FIG. 2

In a water bath that can maintain reactants and a reactor temperature at0° C. with a thermometer, a 100 ml of one-circle rounded bottom flask(flask) having a stirrer is placed. 3 ml of dichloromethane anhydride,0.19 g (0.66 mmol) of thioacetic acid 4-hydroxymethyl-2,6-dinitro-benzylester 251, and 0.053 ml (0.66 mmol) of pyridine were mixed in the flask.After stirring the mixture for approximately 10 minutes at temperaturemaintained of 0° C., 0.136 g (0.66 mmol) of trichlorophosgene was addedto the mixture and stirred for 6 hours.

The mixture reactants were poured into a distilled water containing ice,and stirred for approximately 10 minutes. After extracting ethyl ether,the solution was concentrated by removing the ethyl ether.Consequentially, 0.22 g (0.63 mmol) of white solid, i.e.,4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate 255 wasobtained purifying through a silica gel chromatography column. In thiscase, yield was 95%.

The structure of the product was examined using a hydrogen nuclearmagnetic resonance (NMR), and found that it matched the structure ofcompound numeral 255 depicted in FIG. 2. The hydrogen NMR obtained was[¹H NMR (400 MHz, CDCl₃) (ppm): 8.13 (2H, s), 5.42 (2H, s), 4.62 (2H,s), 2.26 (3H, S)]

Synthesis of thioacetic acid2.6-dinitro-4-(4.5.9.10-tetrahydro-2-ylcarbamoyloxy methyl)-benzyl ester275 in FIG. 2

In a water bath that can maintain reactants and a reactor temperature at25° C. with a thermometer, a 100 ml of one-circle rounded bottom flask(flask) having a stirrer is placed. 20 ml of dichloromethane anhydride,0.093 g (0.42 mmol) of 4,5,9,10-tetrahydro-pyren-2-yl-amine 235, and0.058 ml (0.4 mmol) triethylamine were mixed in the flask. Afterstirring the mixture for 10 minutes, 0.23 g (0.66 mmol) of4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate 255 was addedslowly. After stirring the mixture reactants for approximately 1 hour,0.049 g (0.4 mmol) of dimethylaminopyridine was added, and mixed forapproximately 24 hours.

White solid precipitations were produced as the reaction progresses.After collecting the white solid precipitations by filtering, the whitesolid precipitations were dissolved in tetrahydrofurane to tryre-crystallization. As the result of re-crystallization which wasperformed by adding hexane to the solution, 0.20 g of white solid wasobtained. In this case, yield was 95%.

The structure of the product was examined using a hydrogen nuclearmagnetic resonance (NMR), and found that it matched the structure ofcompound numeral 275 depicted in FIG. 2. The hydrogen NMR obtained was[¹H NMR (400 MHz, DMSO-d₆) (ppm): 9.90 (s, 1H), 8.37 (s, 2H), 7.22 (s,2H), 7.07 (s, 3H), 5.31 (s, 2H), 4.50 (s, 2H), 2.78 (s, 8H), 2.30 (s,3H). ¹³C NMR (400 MHz, DMSO-d₆) (ppm): 194.7, 153.3, 150.7, 140.3,138.1, 136.1, 134.6, 130.3, 128.0, 126.9, 126.3, 125.4, 116.4, 116.0,63.9, 30.2, 28.1, 25.6, 25.2.]

Formation of Molecular Electronic Device Thin Film 295 in FIG. 2

A self assembling method was used to fix the obtained compound in theprevious step 275 in FIG. 2 to a nanopore molecular electronic deviceelectrode. In a glove box maintaining oxygen free and anhydrouscondition, 20 ml of bial, 2.67 mg (0.005 mmol) of thioacetic acid2,6-dinitro-4-(4,5,9,10-tetrahydro-2-ylcarbamoyloxy methyl)-benzyl esterare dissolved in a solvent, which is treated to be oxygen free using afreeze-pump-thaw method, at room temperature and stirred for 5 minutes.A nanopore molecular device in which a lower electrode is formed of goldwas immersed in the above solution for 24 hours. After taking thenanopore molecular device out of the solution, it was sequentiallywashed with alcohol, ethanol, and distilled water.

The formation of self assembling molecular film 297 (in FIG. 2) on asurface of the gold electrode can be proved by quartz crystalmicrobalance (QCM) data in which oscillation is reduced due to theadherence of organic molecules on the surface of the gold electrode astime passes.

FIG. 3 is a QCM data graph for proving existence of self assemblingmolecular film formed on a surface of a gold electrode. Referring toFIG. 3, the QCM data shows that unit molecular films are saturated onthe surface of the gold electrode at approximately 1,200 second aftercommencing the formation of the self assembling molecular film. Thesaturation state in FIG. 3 was obtained when a concentration of compound275 dissolved in DMF was approximately 9.188×10⁻¹¹ mol. The compoundderivative synthesized in this manner according to an embodiment of thepresent invention has a thiol radical at the end portion of themolecular electron acceptor, thereby effectively forming self assemblingmolecular films on a surface of a metal electrode.

Manufacturing a Molecular Electronic Device (FIG. 6) and an Embodimentof Diode Device Characteristic

A molecular device having a gold electrode, a surface of which has selfassembling molecular films was dried in a low temperature vacuum oven(40° C., 10⁻³ Torr) for more than 2 hours. The molecular device wasattached to a deposition equipment which is maintained pressure at 10−6Torr and temperature at −78° C. By depositing an upper electrode on themolecular device, a formation of a molecular electronic device having aself assembling molecular film between two electrodes was achieved.

FIGS. 4A and 4B are schematic drawings for describing an operationprinciple of a molecular diode device to which the compound according tothe embodiment of the present invention is applied. FIG. 4C is a graphshowing a current-voltage characteristic of a unit molecular diodedevice.

Referring to FIG. 4A, as mentioned earlier, a self assembling molecularfilm 295 from the compound numeral 275 in FIG. 2 is formed on a surfaceof the gold electrode, i.e., a first electrode 297. At this time, thecompound constituting the self assembling molecular film 295 acts as anelectron donor-spacer-electron acceptor as depicted in FIG. 4A. When asecond electrode, i.e., a negative electrode facing the first electrode,i.e., a positive electrode, is formed by a method described earlier likea deposition method, a molecular diode device capable of operating asthe diode circuit 300 depicted in FIG. 4B is formed.

Measurements of current vs. voltage showing a rectifying characteristicof the molecular diode device is shown in FIG. 4C.

The molecular diode device can be configured in many different arrays ina molecular device. FIG. 5 is a schematic drawing of molecular diodedevices arranged in an array of 3×3.

Referring to FIG. 5, a plurality of patterned and parted lowerelectrodes 297 are formed of a metal like gold on a substrate 400. Selfassembling molecular films 295 by self bonding are formed on the lowerelectrodes 297 using the compound according to the embodiment of thepresent invention. The self assembling molecular films 295 can bepatterned unit device by unit device using a variety of patterningmethods like selective exposure of the lower electrode 297. Afterforming unit devices of self assembling molecular film 295,respectively, on the lower electrode 297, a plurality of patterned upperelectrode 299 are formed on the self assembling molecular films 295.

In this manner, a molecular device in which an array of molecular diodedevices is formed as a unit device on a substrate 400 can be formed.

While, the molecular device can be configured to an AND gate or an ORgate by arranging the molecular diode devices in an array of 2×2.

FIGS. 6A and 6B are schematic drawings of an AND gate circuit to becomposed of molecular devices and operation of the same.

Referring to FIGS. 6A and 6B, the molecular diode device configured asin FIG. 4 according to the embodiment of the present invention can beconfigured to an AND gate by arranging in an array of 2×2 as shown inFIG. 6A. In this case, the overall array device can operate as shown inFIG. 6B.

FIGS. 7A and 7B are schematic drawings of an OR gate circuit to becomposed of molecular device and operation of the same.

Referring to FIGS. 7A and 7B, the molecular diode device configured asin FIG. 4 according to the embodiment of the present invention can beconfigured to an OR gate by arranging in an array of 2×2 as shown inFIG. 7A. In this case, the overall array device can operate as shown inFIG. 7B.

The compound according to the embodiment of the present invention can beused as a material for realizing a rectifying characteristic or aswitching characteristic by introducing to a molecular device. Themolecular device composed of the compound according to the embodiment ofthe present invention can be structured to a logic circuit device suchas OR, XOR, or AND.

According to the detailed description of the present invention, there isprovided a new compound, i.e., 4,5,9,10-tetrahydro-pyren-2-yl-carbamicacid 4-mercaptomethyl-3,5-dinitro-benzyl ester that can realize arectifying characteristic by disposing between two metal electrodes.Also, it is provided a method of synthesizing the compound.

The compound according to the present invention can be used as anelectron donor-acceptor organic material in a new molecular electronicdevice having a molecular rectifying characteristic. Particularly, ahorizontal or a vertical type of molecular electronic device having arectifying characteristic or an arrayed device of the compound can bemanufactured by using the above organic material.

Also, the compound according to the present invention can effectivelyform a self assembling molecular film on a surface of a metal electrodesuch as gold electrode by means of combining between the metal electrodeand an end portion of the compound. That is, the formation of the selfassembling molecular film on the surface of the gold electrode ispossible because of the thiol radical which is an end portion of thecompound according to the present invention.

Accordingly, a molecular electronic device can be structured by placingan upper electrode on the self assembling molecular film formed on thesurface of the metal electrode by which combined with the newsynthesized compound.

A fundamental characteristic, i.e., the rectifying characteristic of thedevice can be measured by measuring the current-voltage and direction ofcurrent flow between the two electrodes. Such characteristics can bedirectly measured on the surface of the self assembling molecular filmby using a conducting probe atomic force microscopy (CP-AFM) or ascanning tunneling microscopy (STM).

While this invention has been particularly shown and described a portionof the compound synthesized according to the embodiments of the presentinvention, it will be understood by those skilled in the art thatvarious changes in form and details may be made therein withoutdeparting from the sprit and scope of the invention as defined by theappended claims.

1. A molecular diode device comprising: a first electrode; a secondelectrode opposing the first electrode; and a molecular film formed on asurface of the second electrode by combining a compound having followingchemical formula with the second electrode.

where R represents one of hydrogen H, methyl radical, alkyl radical, andacetyl radical that reacts with the surface of the second electrode, nrepresents an integer between 1 and
 25. 2. A molecular logic devicecomprising: a first electrode; a second electrode opposing side of thefirst electrode; and a logic gate arranged by molecular diode device asa unit device, wherein the molecular diode device includes a molecularfilm formed by combining between a compound having a following chemicalformula and the second electrode.

where R represents one of hydrogen H, methyl radical, alkyl radical, andacetyl radical that reacts with the surface of the second electrode, nrepresents an integer between 1 and
 25. 3. A method of synthesizing acompound comprising: preparing 4,5,9,10-tetrahydro-pyren-2-yl-amine;preparing 4-acetylsulfanyl methyl-3-5-dinitro-benzyl chloroformate; andobtaining a compound having a following chemical formula by a couplingreaction between 4,5,9,10-tetrahydro-pyren-2-yl-amine and4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate, so that thecompound performs molecular rectifying action.

where R represents one of hydrogen H, methyl radical, alkyl radical, andacetyl radical, and n represents an integer between 1 and
 25. 4. Themethod of claim 3, wherein the R is acetyl radical, and n is one.
 5. Themethod of claim 3, wherein the preparing the4,5,9,10-tetrahydro-pyren-2-yl-amine comprises: synthesizing2-nitro-4,5,9,10-tetrahydro-pyrene by reacting tetrahydro-pyrene withnitric acid; and synthesizing the 4,5,9,10-tetrahydro-pyren-2-yl-amineby reducing the 2-nitro-4,5,9,10-tetrahydro-pyrene.
 6. The method ofclaim 3, wherein the reduction reaction uses tin chloride (SnCl₂) as acatalyst.
 7. The method of claim 3, wherein the preparing the4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate comprises:preparing thioacetic acid 4-hydroxymethyl-2,6-dinitro-benzyl ester; andsynthesizing 4-acetylsulfanyl methyl-3,5-dinitro-benzyl chloroformate byreacting thioacetic acid 4-hydroxymethyl-2,6-dinitro-benzyl ester withtrichlorophosgene.
 8. The method of claim 3 further comprising an actionto activate the 4,5,9,10-tetrahydro-pyren-2-yl-amine using a basiccatalyst before coupling reaction.
 9. The method of claim 8, wherein thebasic catalyst is triethylamine as a third amine radical.
 10. The methodof claim 3, wherein the coupling reaction is performed using a pyridinegroup catalyst.
 11. The method of claim 10, wherein the pyridine groupcatalyst is dimethylaminopyridine.
 12. A method of manufacturing amolecular electronic device comprising: preparing4,5,9,10-tetrahydro-pyren-2-yl-amine; preparing 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate; synthesizing a compound havinga following chemical formula by a coupling reaction of the4,5,9,10-tetrahydro-pyren-2-yl-amine with the 4-acetylsulfanylmethyl-3,5-dinitro-benzyl chloroformate, so that the compound performsmolecular rectifying action; forming a molecular film by combining thecompound with a surface of a first electrode; and forming a secondelectrode on the molecular film.

where R represents one of hydrogen H, methyl radical, alkyl radical, andacetyl radical, and n represents an integer between 1 and
 25. 13. Themethod of claim 12, wherein the molecular film is self assembling formby a reaction between R of the compound and the surface of the firstelectrode.